The present invention pertains generally to simulators and more specifically to a variable feel side stick controller. Airplane control systems have generally relied on powered hydraulic systems to steer the plane. By using these powered hydraulic control systems, feedback forces from the airplane controls which are prevalent in mechanical link systems are often times greatly changed or even eliminated. This tactile feedback provides an indication to the operator of the aircraft of how far he had moved the side stick from the zero position.
The conventional method of achieving these feedback forces has been to project the hemispherical motion of the side stick onto a horizontal Cartesian plane and thereafter using springs to independently restrict motion in both the X and Y directions. This method of providing feedback forces has proven adequate for small angular displacements of the stick and small restraining forces. However, angular stick displacements which are fairly large, e.g., up to 50 degrees, and high magnitude retaining forces, e.g., up to a hundred pounds or more, cannot be uniformly provided using the spring arrangement.
Presumably a set of feedback forces can be designed to provide optimum pilot response. For example, it would be desirable to vary the force differential on the side stick proportionally to the displacement of the side stick and test pilots for optimum response. Similarly, the ability to independently vary the feedback force on the side stick proportionally to the angular velocity of the side stick would provide empirical data for optimum feedback of this type of force system, in addition. Spring systems have been unable to independently vary these parameters so that optimum pilot response may be tested.
At the same time a system has been needed which was capable of monitoring stick position and feedback force with high resolution, i.e., within one degree and one-half pound, respectively. Also, the depth of the device should allow the operator to sit during the testing periods in a comfortable position such that he can comfortably reach the side stick and maintain a relaxed posture during any maneuver of the stick.
It is therefore an object of the present invention to provide an improved variable feel side stick controller.
It is also an object of the present invention to provide a variable feel side stick controller which is capable of independently varying feedback forces proportional to displacements and angular velocity.
Another object of the present invention is to provide a variable feel side stick controller which is capable of providing isotonic feedback forces.
Another object of the present invention is to provide a variable feel side stick controller which is capable of providing linear feedback forces over large displacement angles.
Another object of the present invention is to provide a variable feel side stick controller capable of providing high magnitude linear feedback forces.
Another object of the present invention is to provide a variable feel side stick controller capable of monitoring side stick position with high resolution.
Another object of the present invention is to provide a variable feel side stick controller which is capable of monitoring feedback forces with high resolution.
Another object of the present invention is to provide a variable feel side stick controller which is compact in design allowing an operator to sit during operation of the side stick and maintain a relaxed posture during any maneuver of the stick.
Another object of the present invention is to provide a variable feel side stick controller which is capable of providing a symmetrical and non-linear feedback force to compensate anthropomorphic irregularities.
Other objects and further scope of applicability of the present invention will become apparent in the detailed description hereinafter. The detailed description indicating the preferred embodiment of the invention is given only by way of illustration since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from the detailed description. The foregoing abstract of the disclosure is for the purpose of providing a non-legal brief statement to serve as a searching and scanning tool for scientists, engineers and researchers and is not intended to limit the scope of the invention as disclosed herein nor is it intended to be used in interpreting or in any way limiting the scope or fair meaning of the appended claims.